In the manufacture of a semiconductor device, a method is known in which a plurality of semiconductor chips mounted on a main surface of a substrate are block-molded with one resin enclosure, and then the resin enclosure and the substrate are simultaneously separated into respective semiconductor chips. These chips are used in many of today's popular electronic devices, such as personal audio/video players, cellular telephones, and high definition television. In the manufacturing process, molten encapsulant, such as resin or epoxy molding compound (EMC) is injected, under constant pressure, into a mold cavity containing leadframes and integrated circuits. As the molten encapsulant moves through the mold cavity, it is possible for air within the mold cavity to become trapped. This trapped air causes voids in the encapsulant that makes some packages defective.
In an effort to design molds that assist in the resolution of the void problem, modern molds have air vents arranged opposite the mold gate that acts as an inlet for the molten encapsulant. The air vents assisted in reducing the pressure required to fill the mold and reduced the occurrence of voids in the packages. Care must be taken to exhaust the air at a correct rate. The air is used to develop a back pressure within the mold assuring the flow of molding compound into all areas of the mold enclosure.
As devices get progressively smaller and the packages get thinner, voids persist in the package structure. Many approaches have been investigated to resolve the manufacturing fall-out caused by voids in the packages. To date there hasn't been a completely successful solution for flipchip quad leadless packages (FC-QLP). Due to the thin nature of the packages and the openness of the leadframes, air is pressured into spaces that are difficult to vent.
Thus, a need still remains for a solution to the package void issues in flipchip quad leadless packages. In view of the demand for high volume very thin packages for electronic devices, it is increasingly critical that answers be found to these problems. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.